-LRB- CNN -RRB- -- Former 100 meter world record holder Asafa Powell has pulled out of the world championships in Daegu , which are set to get under way on Saturday .

Jamaica 's Powell , who took 100m bronze at the last championships in Berlin two years ago , was expected to be one of the main challengers to his compatriot and reigning champion Usain Bolt .

The 28-year-old is the fastest man in the world this year , a 9.78 second run in Lausanne , but a statement from his management company confirmed he will be absent from the biennial event with a groin injury .

`` Asafa Powell has officially withdrawn from the 100m event in Daegu citing a continued groin strain , '' read the statement . `` Powell suffered a groin strain in Budapest on July 30 and has had recurring tightness and pain ever since .

`` After Budapest , Asafa missed eight days of training before he could attempt to sprint again . When he returned to the track he was able to sprint but it caused the groin to flare up .

Despite missing out on the individual event , Powell could be part of the Jamaican 4 x 100m relay squad which claimed gold in Berlin and also at the 2008 Olympic Games in Beijing .

`` He has received all sorts of treatments over the past two weeks in the hope of being prepared to run the 100m here in Daegu , '' continued the statement .

`` Asafa is very disappointed to say the least . He was really hoping to be able to run in what was going to be one of the most anticipated races of the championships . He is still optimistic to be able to run the relay . ''

His absence and that of leading American Tyson Gay would appear to leave the way clear for Bolt to retain his title , but the world record holder told gathered reporters Thursday that was short of his very best form after battling back from injuries that curtailed his 2010 season .

`` I would n't say it 's 100 percent but I 'm happy with where it is and I 'm going out there to do my best , '' he said .

`` This for me is a comeback season from injury . I have been working really hard this season to get back in tip-top shape . '' Bolt added ,

Meanwhile , former Olympic gold medallists Sebastian Coe and Sergey Bubka have been elected as vice-presidents of the International Association of Athletics Federations -LRB- IAAF -RRB- .

Five men were in the running for four positions , with Qatari Dahlan Al-Hamad and Robert Hersh of the U.S. the other two people voted in .

A second vote was required to decide the four successful candidates after a malfunction in the electronic voting system caused the body 's president Lamine Diack to order a revote .

Initially , former Ukrainian pole-vaulter and gold medallist at the 1988 Olympics in Seoul Bubka missed out on election to Canadian Abby Hoffman . Bubka was voted in via a manual vote following the system error .

Coe , a two-time Olympic gold medal winner over 1500m , dismissed suggestions of foul play and insisted it was purely a glitch which caused the re-vote .

`` We would have preferred the technology to work better but it has failed us and we had to go back to a manual vote , '' Coe told British newspaper The Guardian . `` There was just a technical glitch -- there is nothing else involved and we have to live with it .

`` These things do happen . I instinctively thought it looked a bit of a rogue result -LSB- but -RSB- I 'm no great believer in conspiracy theories . Clearly something was n't working . ''

Senegalese chief Diack was re-elected as president unopposed , with a majority of 169 to 29 after a second ballot .

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Asafa Powell pulls out of 100m at world championships through injury

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Powell was set to be main challenger to ddefendingchampion Usain Bolt

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Bolt rules out breaking his own world 100m record at championships

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Sebastan Coe and Sergey Bubka win influential positions in IAAF